Which sequence correctly describes the physical steps of forming sedimentary rock from weathered material?

• A. Weathering, erosion, transportation, deposition, burial, and lithification
• B. Erosion, weathering, deposition, burial, and lithification
• C. Deposition, weathering, erosion, lithification, burial
• D. Burial, lithification, weathering, erosion, deposition

Answer: (A)

Sedimentary rocks come from pieces of preexisting rocks that are broken down and then moved, settled, and finally hardened. Weathering creates the sediment by breaking apart the original rock. Erosion and transportation carry those loose grains away from their source. When the environment slows down, the sediment settles and accumulates in layers through deposition. Over time, more layers pile on, burying the bottom sediments, and the weight compresses them. At the same time, minerals precipitate and bind the grains together in lithification, turning loose sediment into solid rock. That exact sequence—weathering, erosion, transportation, deposition, burial, lithification—best describes how sedimentary rock forms.

Other sequences place steps out of order, such as creating sediment after it should be deposited or burying before there is sediment to bury, which doesn’t reflect the actual process.